印制板液态感光阻焊油墨的工艺控制

本文介绍印制板液态感光阻焊油墨的工艺流程、工艺控制，并对生产中较常出现的几种质量问题进行讨论，进而提出解决措施。     

Liquid Crystal Television Spatial Light Modulator

The liquid crystal televison spatia light modulator(LCTVSLM)characterized is usable in optical processing applications.e.g.,optical pattern recognition,associative memory,optical computing,correlation detection and optical data processing systems.The array performance and real-time optical correlation applications are reviewed.     

离子液体催化苯酚与叔丁醇烷基化反应

 研究了SO₃H-功能化离子液体的合成、表征及其催化苯酚与叔丁醇(TBA)烷基化反应的性能. 考察了反应时间t、反应温度T、反应物摩尔比及离子液体(IL)用量等因素对反应性能的影响, 并考察了离子液体的重复使用性能. 结果表明, 在T=70℃、t=420min、n(Phenol):n(TBA):n(IL)=1:1:1的优化反应条件下, 苯酚的转化率可以达到79.6%, 邻-叔丁基苯酚的选择性达到了52.4%. 离子液体重复使用4次, 其活性基本不变.     

Thermal stratification in ribbed liquid hydrogen storage tanks

A significant decrease in the degree of thermal stratification is demonstrated by improvising transverse wall ribs on the inner cylindrical surfaces of large liquid hydrogen storage tanks. The ribbed surfaces are modeled as fins and a conjugate transient heat transfer problem is formulated for predicting flow currents and heat transfer. Turbulent Rayleigh numbers between 1.2×10¹²$1.2\times {10}^{12}$ and 6×10¹⁶$6\times {10}^{16}$ are considered. A stratification parameter based on the moment of energy is defined to quantify the degree of stratification and this parameter is seen to be about 30% lower for the ribbed tanks. The degree of stratification is not sensitive to changes in the ratio of the rib height to the spacing between the ribs. The transient free convection is shown to be characterized by the parameter Fo×Ra^0.15$\mathrm{Fo}\times {\mathrm{Ra}}^{0.15}$. The process of stratification takes place more slowly in the ribbed tanks than in smooth-walled tanks. The free convective heat transfer coefficient for tanks having ribbed surface is also seen to be significantly lower. Incorporation of ribs over the inner surface of the insulated tanks is demonstrated to offer a simple means of reducing the stratification and boil-off losses.     

大功率速调管发射机水冷系统的设计

雷达发射机中大功率器件(如速调管)的强迫液体冷却是一种常用的冷却方式。本文根据某雷达发射机冷却系统的设计.介绍了大功率速调管发射机水冷系统的设计方法。     

Microwave assisted synthesis of ZnO nanoparticles in ionic liquid [Bmim]cl and their photocatalytic investigation

In this study, ZnO nanoparticles were synthesized based on the chemical reaction of zinc acetate and NaOH in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) under microwave irradiation. The prepared ZnO were characterized by utilizing various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy, FT-IR spectroscopy, and BET method. XRD pattern reveals the produced ZnO has hexagonal structure and the images of SEM and TEM also reveal it consists of nanoparticles with an average size between 15 and 25 nm. The role of the ionic liquid on morphology of ZnO was investigated. For this purpose, a control ZnO sample was prepared without using any [Bmim]Cl. Photocatalytic properties of the synthesized ZnO on degradation of malachite green dye as model pollutant was investigated. The effect of various parameters such as pH, concentration of the dye and catalyst on the degradation of malachite green was investigated. In order to explore the mechanism of photocatalytic degradation of malachite green, scavenger addition method has been employed. It is found that hydroxide radicals are main reactive species for the degradation.     

Electrochromic Polymer‐Dispersed Liquid‐Crystal Film: A New Bifunctional Device

Polymer‐dispersed liquid crystals (PDLCs) are liquid‐crystal dispersions within a polymer matrix. These films can be changed from an opaque to a transparent state by applying a suitable alternating‐current electric field. PDLCs have attracted the interest of researchers for their applications as light shutters, smart windows, and active displays. For such applications, electrochromic devices, which change color as a result of electrochemical reactions, have also become a recent focus of research. Herein, we report our preliminary results on bifunctional devices based on PDLCs that host electrochromic guest molecules. Such devices allow both an independent and fast switching from a scattering opaque state to a transmissive transparent state owing to liquid‐crystal reorientation and a color change from white (pale yellow) to dark blue, due to either oxidation or reduction of the electrochromic molecules.     

液晶运动图像投影仪

由产生图像的液晶显示元件，投影图像的光学机构和显示屏即构成液晶运动图像投影仪。液晶材料可将图像信息暂时储存，称为储存效应。连续图像投影方法是，在液晶材料中产生图像并暂时储存起来，将投影光源对准液晶材料，然后作为液晶透射或散射光函数的图像投影到投影屏上，可连续地产生投影图像。     

用液氦致冷的球载远红外光度计

介绍供观测银心和银道面红外辐射用的快速扫描远红外光度计，光度计的主要元件是用液氦致冷的锗测辐射热探测器，本文还介绍了光度计的总体考虑，各部件的结构，定标设备和观测结果。     

一种新型超声波液位计的开发与研制

本文介绍了超声波液位计利用声呐原理，采用非接触测量方法，可测量高温，高压等密闭容器内液位高度利用“三传感器法”测量超声脉冲的往返时间，从而直接获取液位高度，而与超声波在液体介质中的传播速度无关。